/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.dili.dd.flume.plugin.exthdfs;

import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.LongWritable;

import java.util.Collections;

public class HDFSWritableSerializer implements SequenceFileSerializer {

    private BytesWritable makeByteWritable(Event e) {
        BytesWritable bytesObject = new BytesWritable();
        bytesObject.set(e.getBody(), 0, e.getBody().length);
        return bytesObject;
    }

    @Override
    public Class<LongWritable> getKeyClass() {
        return LongWritable.class;
    }

    @Override
    public Class<BytesWritable> getValueClass() {
        return BytesWritable.class;
    }

    @Override
    public Iterable<Record> serialize(Event e) {
        Object key = getKey(e);
        Object value = getValue(e);
        return Collections.singletonList(new Record(key, value));
    }

    private Object getKey(Event e) {
        String timestamp = e.getHeaders().get("timestamp");
        long eventStamp;

        if (timestamp == null) {
            eventStamp = System.currentTimeMillis();
        } else {
            eventStamp = Long.valueOf(timestamp);
        }
        return new LongWritable(eventStamp);
    }

    private Object getValue(Event e) {
        return makeByteWritable(e);
    }

    public static class Builder implements SequenceFileSerializer.Builder {

        @Override
        public SequenceFileSerializer build(Context context) {
            return new HDFSWritableSerializer();
        }

    }

}
